Physics has proven that ultra-light dark matter does not exist in principle

© Fotolia / kamilsezaiТак the artist imagined stolknovenie ultra-small particlesPhysics has proven that ultra-light dark matter does not exist in principle© Fotolia / kamilsezai

. By observing the movement of neutrons and atoms of heavy metals at ultralow temperatures revealed that the mild forms of axions, particles of «light» dark matter, can not exist in principle, which again complicate her quest, said in an article published in the journal Physical Review X.

«These results open a new window for the search for dark matter. They indicate that axions cannot exist in principle in a very wide range of masses and energies, which significantly reduces the field where we should look for traces of this mysterious substance. We can say that our search now begins again,» said Nicholas Ayres (Ayres Nicholas) from the University of Sussex (UK).

Quite a long time, scientists believed that the universe consists of the matter that we see, and that is the basis of all stars, black holes, nebulae, clusters, dust and planets. But the first observations of the speed of movement of stars in neighboring galaxies showed that the lights on their edges move them to an impossibly high velocity, which was about 10 times higher than shown by the calculations on the basis of mass of all bodies in them.

The reason for this, as scientists believe today, was the so-called dark matter – the mysterious substance, whose share accounts for about 75% of the mass of matter in the Universe. Usually, each galaxy is about 8-10 times more dark matter than visible «cousin», and this dark matter holds the stars in place and not allow them to «scatter».

Today, almost all scientists believe in the existence of dark matter, but its properties other than its apparent gravitational effect on galaxies and clusters of galaxies remain a mystery and subject of debate among astrophysicists and cosmologists. Quite a long time scientists have assumed that it is composed of heavy and «cold» particles»winow», did not show themselves, except drawing visible accumulations of matter.

Unsuccessful search «vinow» in the last two decades has led many theorists to believe that dark matter actually could be «light and fluffy» and consist of so-called axions – light particles, similar in mass and properties of the neutrino.

Ayres and his colleagues accidentally discovered that the easiest types of axions, which are often theorists say, cannot exist in principle, analyzing the results of the CryoEDM experiment, it is far from cosmology and dark matter.

This project, says physicist, was started two decades years ago for the accurate measurement of one of the most fundamental small value of the dipole moment of the neutron. By this word I understand the physics of how distributed the positive and negative charge within the neutron, and the neutron is really a fully electrically neutral particle.

In the framework of the CryoEDM physicists are trying to find the dipole moment of the neutron, and watching the «soup» of single atoms of a rare isotope of mercury and neutrons react well to sudden changes in the direction and strength of the electric field within which they are located. If the neutron has a dipole moment, its spin will «twitch» in a special way at the «turn» field, «see», observing the changing polarization of the particles.

Analyzing the data obtained by the detectors CryoEDM in the first period of their work, the scientists noticed that the accuracy of these observations was so great that the behavior of the mercury atoms and neutrons will be greatly affected by the interaction of subatomic particles called axions. In other words, if axions exist, they will cause another type of waves, and their strength will depend on the mass of dark matter particles.

As shown by reanalysis of the data CryoEDM, nothing like the behavior of mercury and neutrons were observed, which indicates a fundamental lack of the lightest versions of axions whose mass is in the millions and tens of billions of times smaller than that of the electron.

Similar results, as stressed by Ayres, did not preclude the existence of other types of axions, but significantly narrow the dimensions of the field, where their existence remains valid from the point of view of science. It is possible that dark matter consists of superheavy or ultralight particles similar to visible matter, and is of an entirely different nature, which we do not guess, conclude the authors.